Step 1 Steam, boil or microwave pumpkin until tender. Drain well and mash.
Step 2 Process bread to crumbs in a food processor. Remove to a bowl. Process chickpeas and pecans until a paste forms. Add to breadcrumbs along with pumpkin and onions. Combine well, then shape into 4 even-sized patties. Chill for 30 minutes.
Step 3 Preheat oven to 200ºC. Line a baking tray with baking paper. Spray patties with oil and bake for 15 minutes. Turn over, spray again, and cook for another 10 minutes.
Step 4 Meanwhile, combine hummus with yoghurt. Add coriander.
Step 5 Place a slice of toast onto each plate. Spread with hummus mixture, then top with patty, cucumber, capsicum, lettuce and remaining toast. Serve immediately.